Title: Expanders, groups and applications Eyal Rozenman Center for the Mathematics of Information California Institute of Technology Abstract: Last week we defined expanders and how to get them from groups. In the upcoming talk I'll present some beautiful applications: - Constructions of good error correcting codes, and the relation to expanders on the group (Z_2)^n. - Deterministic simulation of a random walk on a graph and its application for solving connectivity questions on the graph. - How to generate a random element in a group given only generators of the group, and the relation to expanders on the group of symmetries of free groups. - The Banach-Tarski Paradox and the relation to embedding expanders in the group of 3-dimensional rotations